1. Field of the Invention
The present invention relates to dental measurement instruments.
2. Related Art
In the field of aesthetic restorative dentistry, it is highly desirable to take pre-operative measurements in planning the restorative or surgical procedure. In addition, intra-operative measurements are critical in assessing and predicting the aesthetic outcome of the procedure.
In aesthetic dental procedures (and also in reconstructive and restorative dentistry as well) it is desirable to perform restorative and surgical procedures in accordance with aesthetic considerations so that the operative result is not only medically acceptable, but also aesthetically acceptable. Such considerations are based on measurements of the teeth and aesthetic principles based on measurements. In this regard, see, for example, Ward, Daniel H., “Proportional Smile Design Using the Recurring Esthetic Dental (RED) Proportion,” Dental Clinics of North America 2001, 45, No. 1, pgs. 143–154 (2001.)
A first exemplary context for such measurements is establishing the proper tooth proportions and length to width dimensions in reconstructive, restorative and aesthetic tooth analysis. There are three structures that compose the smile—the lips, the gingiva, and the teeth. They must have a harmonious relationship with each other for acceptable facial, dentofacial and dental aesthetic appearance to exist. This harmony results if each of these entities is in proper proportion to the other two. Further, the tooth itself must be properly dimensionally proportioned in order to present the most pleasing smile. Tooth dimensions and proportions also guide the clinician during treatment, specifically in designing the restoration of the tooth and in altering the periodontium. Thus, the need exists to achieve proper and accurate tooth dimension and proportion for each clinical situation.
Heretofore, clinical molds were made of teeth for aesthetic analysis, dimensional measurements were taken from these molds or from positives made from such molds, and these measurements were then manipulated by elaborate computer software to determine the appropriate dimensional proportions of the teeth for the desired aesthetic result. Alternatively, direct dimensional measurements were taken from the patient's teeth, the measurements were entered into data charts, and then mathematical calculations were made with this data to produce a set of desired numerical values. In both of these approaches, the clinician would have to take the numerical output and then use that numerical information along with a ruler intraoperatively to guide the surgical procedure. This approach was clumsy and prone to error.
A second exemplary context for dimensional measurements is its application in aesthetic crown lengthening surgical procedures. Previously, this procedure was accomplished through the use of surgical templates that had limited use with respect to assessment of the osseous crest, biologic width requirements, and clinical crown visualization. All three of these parameters must be able to be visualized and assessed simultaneously in order to create the proper aesthetic, restorative, and periodontal relationship for the dental patient. Further, over time wear and tear on the teeth causes compensatory eruption of the tooth in order to allow confronting contact between corresponding upper and lower teeth. This results in a change in the relative placement of the gingival margin. Desirably, in the foregoing instances the relative length of the clinical crown with respect to that of the biological crown is adjusted to preserve or attain a desired dimensional proportion. The biological crown is the part of the tooth from the crest of the bone to the incisal edge. The clinical crown is the part of the tooth from the gum line, or gingival margin, to the incisal edge and is the portion of the tooth that is normally seen.
Since the heretofore-used surgical templates rely on the use of diagnostic casts, wax-ups, and hardened acrylic overlays on tissue models that cannot be representative of the true clinical scenario, they have limited benefits. In addition, they tend not to fit well, are prone to guesstimation, and are relatively expensive. The use of a ruler, particularly intraoperatively, to measure and give proportions is cumbersome and prone to inaccuracy due to eye fatigue.
A third exemplary context for dimensional measurements is its application in the positioning of the interdental papilla in aesthetic surgical procedures. A fourth exemplary context for dimensional measurements is its application in periodontal bone location or ‘sounding’ in aesthetic surgical procedures. Each of these categories of procedures require careful, precise, and easy measurement.